Underground conduit for electrical conductors



(No Model.

J. RGUMMINGS. UNDERGROUND CONDUIT FOR ELECTRICAL GONDUCTORS. YNo. 497,536.

Patented May 16 Mv WER Jams n {o1-'intimes'.

on Dn'rRorrg)MtonieAN. j

UN DERG so un o con ou IT Fo RELECTRIQ'AL con DuCTo Rs.y

S'IECIFICATIO forming' part of Letters-Patent No. 497,536, dated May 16,1893.

pplication'iiled July 28, i892,

To all whontzlt may concern:

Be it known that I, JAMES F. CUMMINGS, a citizen of the United States, residing'- atDetroitlin theeounty of Waync and Stateof Michigan, have invented certain new end usejful Improvements `inUndergronnd Conduite tween made insections, and further in the pe-A culiar construction of a joint-between the sec'-l tionsfurther in the peculiarI constructionof y the man holeor service bemand further in' l 1for Electrical Conductors, of whichy the fellowing isa specification, 4reference vbeing had thereinlto the'` accompanying. drawings.

. ",'1`his'invention relates to new and usefulimfV provements in underground conduits for elec.

tric,'conductora'andthe invention consists in the', peculiar construction of a-eonduit comprising an .inner and an outer casing concentrlcally arranged with an insulating body be` "the peculiar construction,arrangement and' 'combination of tho various parts. y l

,'lhe method of forming thev conduit herein referred to, I have lmade the subject matter `of a concurrently pending application liled July l2, ISJ-, Serial No. 1130,7et8.

In the accompanying drawings Figure I is avertical ccntrahlongitudinal section through pas the meeting ends of two sections of my con- .duit showing the inner casing partly in televation. liig. 2 isa cross section thereof on line :tf-av. Fig. 3 is a similar section to Fig.

1', showing a preferred form of joint or coup: ling. Fig. l is a similar sect-lon showing still another modification. j Fig-.5 is an end elevation specifically referred to and illustrating the method of.manufacturing thoy conduit. Fig. G is a cross section through a conduit showing-.tho longitudinally divided interior casing'. I"ig.7 is a vertical-section through a manhole, and Fig. S isa plan view thereof, with the cover removed.

A and ll` are two casings preferably of metal piping forming the inner and outer casing of my conduitrespectively.

Upon the casingA, ly wind spil-ally aclamp- ,.ing'1neans,-snch as rope or other suitablev .flexible non-conductor C, leav i n f" a spiral space.

1 between the coils of the-rope.

thus woundis then inserted into thecasing B/the rope or clamping means serving to keepv the inner easing away from the outer casing ,forming an annular passage-way D from endV lhe casing A Santino.' tits/12.' gno man.)

to end between the .coiisof the rope. i I then force in to this annular space any suitable noneonducting lnaterialpsuch as asphaltum, in .liquid form; entirely filling .this space. This fillingis tlien allowed to harden and makes a rigid seetionot conduit as plainly shown in Instead of using an innere-asini; of iron piping, 'as shownin Eig. 1'5'1 may use` air-inner ,easing as shown in;A Fig. 6, composed of two semi-cylindrical blocks E, preferably of wood- .havingcorresponding grooves F forming pas# f sage ways therethrough.. and 1n such constructionI'placethetwo blocks together to form a .oylfindeigandfthen wind it .with a rene, ou

' clamping means place it within'the outercasing, and thenfill the annular space "between the two in the samev manner as before described." These sections ymay bet joined together inA variousy ways dependingr largely Vupon the kind of condnctorwhich it is de signed to carry throughthem. For high tension electric curreutsl preferably use the construction shown in vFigs. 1 and il, and for telephone or telegraph .work I use the construe tion shown in Fignf'la The. coupling shown iii-Fig. l, consists ofa 'clamping sleev'eG made in two halves with :clamping lugs ll' on the sides tightly clamped upon the meeting ends of the sections by .means of clampingl bolts l. .I is a flexible sleeve preferably of rubber which is placed over the joint within the coupling'G and clamped in position. p'l`he coupling is provided with asuitalne aperturev I( through which an insulating eompou nd may be poured into the annular chamber formed between the coupling and sleeve .l as shown at Il'in. Figs. l and l. 'lhe rubber J is used to malte a tightv jointy between the outer tube and couplingsleeves and to prevent-the filling material in Athe'slceve from adhering to the tube which would greatly interfere with the disnnionot the section.

` Instead off'n'sing the packing sleeve J, other `one section to the other of the coupling.

an annular space between the ends olthel outer casing in which I place asuitableinsulating ring O ot' rubber or other material. This ring O serves in a measure the purpose of the packing,rv J, ott the vform described. Around the end of the sections I clamp the two part coupling G and fill in the space within the coupling as previously described. It' desired, fortelephone or telegraph conduits, each section' of 'coupling may be insulated from tl... ether, and tnis may be accomplished in any desired manner. I preferably accom- .plis'h it by placing an insulating ring P between the meeting ends of the sections; this `ring having suitable lateral iianges Q on each side overlapping the ends'of the outer casing. The packing sleeve .I and filling L outside of this ring preventpossibilityof contact from through the medium In Figs. 7and 8,1 have shown my improved man-hole or service box consisting of an open top metallic casing R having inwardly extending lugs Sfupon which rests a detachable frame S extendingto near the top of the casinf,r R, and upon this frame is placed a plate x-i'lfhaving formed thereon an outer'series of ,tacts down through contacts T', and an Vinner seriesA of contacts T2. The conductor is ,brought in through th'e conduit which extends inside of the box and is connected to one of the outerseries of contacts 'l" and thence to one ot the inner contacts, the two inner contacts being connected by a fuse T3, thence to one of the outer con- `1e box to the conduit through 4which it is desired 'to be carried. This arrangement ot' the contacts enables me to arrange the fuse wires ineasy position for replacing in case the 'are burned out, and enables me to make a crossing or to turn a corner without diiculty, and also result in a construction of man hole which is easilymanufactured, assembled or repaired.

What I claim as my invention is l. In an electrical conduit for electrical a non-conductor insulating conductors,

of clamping means upon thesections for holding the parts together, an outer casing surrounding the inner casing, the clamping means forming spacing means to separate the two to leave a continuous inner chamber, and compound in 'said chamber, substantially as described.

2. In an underground conduit for electrical the combination of theinner casing divided longitudinally into sections, of a flexible cord wound spirally about the same and serving to clamp the sections together, an outer casing surrounding said sectional cas- `ing,`saidcord serving to separate the inner outer casing and form a con; l

casingfrom the tinuous spiral chamber from end to endthere of, and anon-conductinginsulatingcompbund filled in said chamber, substantially as described.

3. In an underground conduit for electrical conductors, the combination with'inner conduits, of outer conduits-shorter than the'in-4 ner conduits, clampingmeans between the outerand inner conduits, plugs at the ends of the outer conduit, insulating material between the adjacent plugs and on the inner conduits, and clamping sleeves over the ends oi' the conduits and insulating material, substantially as describe 4. In an electrical conduit, the combination with inner conduits, of outer conduits, spiral spacing means between the conduits, rubber insulating strips at the `junction of adjacent conduits, clamping lating strips and a filling ot' insulating material between the sleeves and strips, substantially as described. I

In testimony whereof I aliix my signature in presence of two witnesses.

`.l AM ES F. CUM MIN GS.

Witnesses: l

M. B. ODounitn'rv, N. L. LrNnor.

sleeves G over the insu- 

